Apparatus for receiving television pictures



Oct. 25, 1932. SCHRUTER APPARATUS FORRECEIVING TELEVISION PICTURES Filed NOV. 12, 1929 INVENTOR FRITZ scHRoTER BY 1 I g ATTORNEY Patented Oct. 25, 1932v UNiTE-o S AT P N FRITZ SCHRGTER, OF BERLIN, GERMANY, ASSIGNOR T TELEFUNKEN GESELLSCH AFT FUR DRAHTLOSE TELEGRAPHIE M. .B.H OF BERLIN,;GERMANY, A CORPORATION OF GERMANY APPARATUS. Eon RECEIVING TELEVISION rio'ruims 1 Application filed November 12, 1929, Serial No. 406,632, and in Germany November 2?, 1928;

Theobject of the'invention is a television receiver based upon the well-known principle of synchronous decomposition or analysis and re-creation or re-composition of the picture at the sendingand the receiving ends,

respectively, and the transmission thereof through electric telegraph impulses. The invention by the aid of comparatively simple means of reduced dimensions of the elements required for picture re-creationmakes it possible to produce atthe receiving end luminous pictures of sufficient fineness.

In connection with the use of the Nipkow disk, the simplest light-control means hereto fore known in IGCGIVGI. apparatus consists of a neon or other type of glow-discharge lamp having a luminous cathode presenting a surface equal'to the picture field of the Nipkow disk. However, the luminous intensity of the picture built up successlvely from surface elements or units is low because of-the fact that of theaggre'gate luminosity of the glow-discharge lamp in each case only the small fraction reaches and impresses'the of a controlled light sourceupon the area approximating a picture line, through the use of appropriate optical means to be hereinafter described. At the same time, the light is moved in such away that this concentrated light will only impinge upon the picture line just being scanned by any appropriate form of scanning or distributer disk. v

7 Details of the invention can be seen from the following specification of an embodiment shown by way of example in the accompanying drawing; wherein:

' Fig. 1 represents a schematic perspective OFFICE-f of a receiver system according to my inven- I tion;;' a l s 7 Fig. 2 shows a side view of the: receiver of Fig. 1 and diagrammatically illustrates a preferred form of scanning disk; and,

Fig.3 shows a suitable light source for use with a receiverof the type shown by Fig. 1. As shown in Fig. 1, a perforated spiral disk 1 serves for thepicture-point. distribution. 1 The disk 1 isrotated at ahigh rate of speed by a synchronous motor 2 which is maintainedin synchronism by any desired means with the corresponding scanning or exploring device mounted at the sending end, such that the speed of the disk may be, for instance, 32 revolutions per second. Inporder to insurea finer division of the picture and still keep the disk dimensions down, the holesor apertures are disposed in'the form of a double spiral so'that, as shown, the whole picture isproduced in the course of two rotations. Hence, by the above illustrated example, the number of transmitted pictures per second is'16, although by appropriate increases or decreases in the disk speed,'the

number of complete pictures transmitted per second may be increased for decreased to suit. conditions.

For the light concentration, as described, a

and for the travel of the light flux, a 'drum 3 isprovided, whichghas supported upon its circumference eight cylindrical lenses, for example, each being parallel to the axis. Theselenses areshowninFigsl and 2 only partially and are identically denoted'by numerals 4.] They are at the same distance, from one another. p p I Parallel to the axis of rotationof the drum 3 is an elongated tubular or slit-shaped glowdischarge lamp'5,the luminosity of which is controlled by the televisor' receiver 26 as to its brightness so that thereby the change between light and dark is produced in the incoming picture in well-known manner.

Thesaid luminous source -5, which has its 9 rear face suitably mirrored or provided with a reflectingdeposit or which is bodily fitted into a mirror, is pictured or reproducedby the rotating rim of cylindrical lenses 4 in the plane of the perforations of the disk'l. This reproduction is at such reduction in size that its image covers a surface corresponding approximately to the product of length and width of a line of holes. However, since the lines of holes in the disk in the case here assumed is a shallow arc, it will be necessary that the field illuminated or scanned by the image of the luminous source 5 upon the disk 1 must be correspondingly wider than a line of holes. However, the tubular or slitshaped light source 5, as shown in Fig. 3, may be given an arcuate curvature so that the image through the cylindrical lens is likewise curved in such a way that it will adhere and be adapted to the curvature of the picture lines. In this manner, the light upon the disk 1 can be condensed slightly more and the luminous source can be utilized still further.

If the rim of cylindrical lenses, by the aid of the Worm-wheelgear 8, 9, and the transmission gearing 10, 11, 12 (by means of a perforated tape) is set into rotation, then the linear image of the luminous source 5 travels a certain distance upon the surface of the disk 1, in the direction indicated by the arrows from the top to the bottom until the next cylindrical lens occupied the location of the preceding one, when the cycle is repeated over again. In order that this migrating image of the light source 5 may fall upon the disk 1 always just at the height or level of the particular line just undergoin scanning, there must be a definite relation between the speed of the disk 1 and that of the rim or circle of lenses 3, 4. In the example here given where. it is assumed 16 pictures are reproduced each second, the rim of lenses must just make two revolutions per second.

The migrating picture of the luminous source 5, in the arrangement here shown, describes a circular path in the plane of the drawing. Thus, if the picture is to be uniformly sharp and luminous upon the scanning or distributor disk 1, no matter what the height or level or what the picture line, it will be seen that the disk 1 should not be a planer surface, but it must inside the peripheral range of the double perforation spiral be toroidally curved all around as shown in Fig. 2. By the eccentric disposition of the light source 5 (Fig. 2), however, the curvature of the picture path may be flattened down with the result that toroid 13 and thus also the curvature of the picture can be made flatter. It is a suitable scheme to cover or fill up the pictures of the disk 1 with a light diffusive medium which, inside the whole angle formed between the traveling picture line and the eye of the observer, luminesces uniformly in all directions. The luminosity, in the presence of equal value of the electric control impulses, will then appear equal to the stationary eye throughout the picture, that is to say, the same above as below, right and left.

The luminous source 5, as in Fig. 8, is con structed as, or consists of, a straight or still. better an arcuate luminous tube with terminal electrodes 6 and 7, filled with a highl luminous gas such as a neon-helium mixture at a suitable pressure. The ensuing light even at a few milliamps will be intensive enough to result in luminous pictures. By choosing different gas fillings for the tube, it is possible to reproduce the pictures in many different colors. The diameter of the luminous tube of 5 amounts, for instance, suitably to 5 mm. when the cylindrical lenses insures a reduction of 4: 1 and when the holes in the distributor disk 1 have a diameter of 1 mm. The disk is then slightly moved out of the picture plane, and as a result uniform luminosity is obtained along an entire arc of the holes in the picture field. When the tube 5 has an arcuate curvature blurred images maylbe dispensed with. For reasons of safet owever, the luminous tube of 5 may be ciosen of a somewhat larger diameter, and then it will be advisable to operate with as large a current as possible in order to compensate for the smaller concentration of the light. Instead of making the light source tubular and of utilizing the light column 111: cidentally produced, it is also possible to use a cathodic glow-discharge between two closely adjacent or opposite electrodes the length of which should correspond to that of the luminous tube or the cylindrical lenses l. What will then be produced in the plane of the disk 1 is a long strip of uniform cathodic glow. Such a glow-discharged lamp having a more or less narrow electrode gap oiiers the advantage of lower ignition and operating potential with an incidental. facilitation in operation of the receiver amplifiers.

It will be apparent from the above description' that the invention is capable of many modifications, and I believe myself entitled to make and use any and all of such modifications as fall fairly within the spirit and scope of the hereinafter appended claims.

Having now described my invention, I claim:

1. In a television system, a rotary scanning disk for tracing point for point intensities of light and shadow in a line for line manner for rebuilding a picture, and a drum provided with elongated lens elements about an axis at right angles to the axis of rotation of said scanning system for causing light issuing from a source internally thereof to trace successive parallel paths across the said scanning element during the rotation thercof.

2. In a television system, a rotary scanning element for tracing point for point intensities of light and shadow in a line forlli'ne manner for rebuilding a picture, and a secondary scanning element revolving about an axis at right angles to the axis of rotation-of said first element, and a plurality of elongated cylindrical lens elements posiw tioned intherim of said secondary scanning element for causing light beams issuing from a source of fluctuating intensity to focus upon said first element totrace' successive parallel paths of'concentrated light across the said scanning element during the rotationthereof" I I i v 3. In a television system, a scanning element adapted to be rotated in such a manner as to cause light beams projected thereon to trace successive parallel paths for rebuilding a picture subject, a drum provided with cylindrical lenses carried upon the outer edge thereof associated with said scanning element and adapted to rotate at a predetermined speed relative thereto about an axis at right angles to the axis of rotation of said scanning element, a source of light contained within said lens drum, and means provided by said lens drum for so focusing the light issuing from said source as to trace successive light paths across said scanning element for concentrating substantially the entire amount of li -ht available from said source within a narrow portion of the total area covered by said scanning element.

1-. In a television system, a scanning element adapted to be rotated in such a manner as to cause light beams projected thereon to trace successive parallel paths for rebuilding a picture subject, a lens drum associated with said scanning element, said lenses being arranged to focus over a width corresponding to the rebuilt picture width, a light source within said drum, and means for rotating said drum about an axis at right angles relative to the axis of rotation of said scanning element at a speed such that light beams passing therethrough are focused along successive parallel paths across said scanning element during each rotationthereof, whereby substantially the entire amount of light available from said source is concentrated upon each of the said scanning elements during the rotation thereof before said light source.

5. In a television system, a scanning element provided With a series of scanning elements about the outer periphery thereof and so arranged as to cause light beams projected thereon to be directed in successive substantially parallel paths, alens drum associated with said scanning disk and having a plurality of cylindrical lenses about the surface thereof, an elongated source of light contained within said lens drumfor directing light outwardly through the lens portion thereof, means for revolving said lens drum ZLDCl'SEIld scanning element at a predetermined speed relative to each other, and means provided by the lenses in the outer periphery of thereof, an elongated source of light contained within said lens drum for directing,

light outwardly through the lens portion thereof, means for revolving said lens drum and said scanning. element at a predetermined speed relative to each other, and means pro vided by'the lensesin the outer periphery of said lens drum for causing the light beams issuing from the said source contained thereinto focus upon successive parallel paths across said spiral scanning element during the rotation thereof, whereby substantially the entire amount of available light is pe-' riodically concentrated upon each path of projected light from saidscanning element.

7. Ina television system, a scanning disk provided witha plurality of scanning elements arranged in a spiral path about the outer periphery thereof for causing light beams passing therethrough to trace successive parallel paths for rebuildinga picture, a source of light adapted to be varied in'intensity-in accordance with received signalling impulses, and a lens drum rotating about an tKl-Sfil) right angles to the axis of rotation of said scannin element interposed between said light sourcerand said scanning element for causing; the light issuing from said source to be successively concentrated along substantially parallel paths corresponding to the path traced by each'in'dividual scanning element thereacross during the rotation of said scanning element and'lens drum relative to each other.

8; In a television system, a toroidal-shaped scanning disk having a plurality of apertures arranged a spiral path about the outer periphery "thereof, means for rotating said scanning element at a predetermined speed, a drum provided with aplurality of elongated lens members mounted about the outer periphery thereof, means for rotating said drum about an axis substantially at-right angles to the axis of rotation of said scanningelement and at a predetermined speed relative thereto, an elongated light source of a length substantially equal to the width of a picture represented'by the spacing of said scanning elements arranged within said drum, and means provided by said elongated lenses about the outer periphery of said drum for tive to a fixed point, whereby the effective amount of available light for rebuilding a picture is Substantially increased. 7

9. In a television system, a rotatable scanning disk having a plurality of apertures arranged in a spiral path about the outer periphery thereof, a rotatable drum disk rotating relative to said scanning disk about an axis at right angles to the axis: of rotation of said scanning disk, an elongated arcuateshaped light source contained within said drum disk, means for varying the. intensity of said light source in accordance with received signalling impulses, a plurality of elongated lens elements arranged in the outer periphery of said drum disk for directing the light issuing from said light source toward said scanning disk and concentrating the light from said source so as to form a succession of substantially parallel lines corresponding to the lines traced by the rotation of the various apertures of the spiral forming said scanning disk, whereby the illumination on vhe rebuilt image is increased.

10. In a television system, a rotatable scanning disk having a plurality of apertures arranged in a spiral path about the outer periphery thereof, a rotatable drum disk rotating relative to said scanning disk about an axis at right angles to the axis of rotation of said scanning disk, an elongated arcuateshaped light source having a curvature corresponding to the curvature of the path traced by each individual aperture of said scanning disk contained within said drum disk, means for varying the intensity of said light source in accordance with received signalling impulses, a plurality of elongated lens elements arranged in the outer periphery of said drum isk for directing substantially the entire amount of light issuing from said source towards said scanning disk and concentrating the light from said source so as to form a succession of light paths corresponding to the lines traced by the rotation of the various apertures of the spiral scanning disk, whereby the illumination of the rebuilt image observable upon viewing the scanning disk is increased substantially.

11. In a television system for the electrooptical reproduction of television images, a drum scanning disk having a plurality of elongated lens elements carried upon the pe- 'iphery thereof, a light source supported within said lens drum and extending transverse thereto for a distance at least equal to the width of said lens elements, means for rotating said lens drum at a predeterminedspeed, whereby the image of said light source is caused to trace in succession a plurality of separate paths of light varying in intensity FRITZ soHRoTER.

QERTH EGATE OF CGRRECTION.

Patent N0. 1,384,232. October 25, 1932.

mm SGHRBTER.

it is hereby izfii'iififi-li ermr aypeais in the printed specification of the *iiifl', QQE'Efi-Ciififi as fallows: Page 1, line 77, for "for" mad "@s; page 2 an? er "bans" inseyt. the word "has", and line 1 claim I, aim er the word "revelving"; and that the said Patent simuid ram? with flies-e aoi'rectimis therein that the same may above numbered patimi;

Letters confarm to the ream-1i @i the ca e is the Patent (Mice.

Signed and seaied iii-w day of Febmary, A. D. 1933.

M. J. Moore! (Sfiill) Acting Commissioner of Patents, 

